Heat exchange apparatus



Sept. 29, 1936. A. R STEVENSON. JR 2,056,023

HEAT EXCHANGE APPARATUS Filed Dec. 29, 1954 Inventor: Alexcrrwder`l F?.Stevehs0h,JT3,

Patented Sept.` 29, 1936 HEAT EXCHANGE APPARATUS Alexander R. Stevenson,Jr., Schenectady, N. Y.,

assignor to General Electric Company, a corporation of New YorkApplication December Z9, 1934, Serial No. 759,673

11 Claims.

My invention relates to heat exchange apparatus suitable for use inrefrigerating machines.

It is an object of my invention to provide an improved heat exchangedevice of the type in which heat is transferred between a casing orother body and a fluid medium.

Another object of my invention is to provide an improved arrangement forcirculating a fluid medium about a heat exchange device.

A further object of my invention isf to provide an improved aircirculating and frost removing device for refrigerator evaporators.

Further objects and advantages of my invention will become apparent asthe following description proceeds, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to land forming apart of this specification.

For a better understanding of my invention reference may be had to theaccompanying drawing in which Fig. 1 is a sectional view of a householdrefrigerator provided with a heat exchange device embodying myinvention; Fig. 2 is a sectional view along the line 2-2 of Fig. 1; Fig.3 is a sectional view along the line 3-3 in Fig. 1, and Fig. 4 is adiagrammatic view of another embodiment of my invention.

Referring now to the drawing, in Figs. 1, 2 and 3 I have shown arefrigerator cabinet having an outer metal wall I Il, a compartment IIto be cooled, an evaporator compartment I2 and a motor and compressorcompartment I3. The compartments II and I2 are formed by inner metalliners Il and I5 respectively and are surrounded by thermal insulationI6. The compartment I3 is not thermally insulated and is provided withlouvers l1 formed in the outer side walls I0 of the cabinet to admit airto cool the motor and condenser. The refrigerating machine is of thegeneral type shown and described in U. S. Letters Patent No. 1,155,780granted to Audiilren and Singrn on October 15, 1915. 'I'he machinecomprises a compression casing I8 and an evaporator I9 secured togetheron a hollow shaft 20 which is mounted to rotate in bearing brackets 2Iand 22 and is driven by a motor 23 through a belt 24. When thecompressor and evaporator are rotated by the motor 23 gaseousrefrigerant is compressed by a compressor within the casing Il and iscooled and liqueed by the circulation of air over the casing. The liquidrefrigerant passes through a conduit arranged in the hollow shaft 20 to.the evaporator I9 where it is vaporized upon the absorption of heat fromthe chamber I2, the vaporized refrigerant being returned to thecompressor.

From the foregoing it will be apparent that it is necessary to providean efficient transfer of heat between the evaporator and the compressor5 casings and the air surrounding them, and also that it is necessary todrive the cooled air from the evaporator compartment I2 into the'compartment I I and to circulate cooling air over the compressor andcondenser.

In accordance with my invention, I provide a plurality of spacedparallel fins 25 on the evaporator I9 and a plurality of spaced parallelns 26 on the compressor casing I8, the fins being arrangedcircumferentially about the evaporator 15 and compressor casing andperpendicular to the axis of rotation. When the evaporator andcompressor casings are rotated the fins induce a circulation of thesurrounding air. In order to use this circulation of air to provide aneillcient 20 transfer of heat between the casings and the surroundingair, and in order to circulate air through the compartments II and I3, Iprovide baille plates 21 and 28 in the compartments I2 and I3respectively and secured to the walls thereof. 25 These bailles arecomb-like in appearance and have teeth 29 and 30' which ilt between thefins 25 and 26 respectively. The teeth 25 and 30 and the bailles 21 and28 are arranged closely adjacent the evaporator I9 and the casing I8,the 30 space shown between them on the drawing being exaggerated forpurposes of illustration. It will be apparent that, as theevaporator I9and the casing I8 are rotated, the air circulated by such rotation willbe diverted or skimmed oiI by 35 the baffles 21 and 28 and will ow awayfrom the casings and, since the compartments I2 and I3 are each dividedby the bafiies on one side of the shaft 20, the currents of air producedwill clrculate across the compartments on the opposite`40 side of theshaft. In order to utilize the circulation of air in the compartment I2to cool the compartment Il, I-provide a semi-cylindrical or arcuatebaille 3|, as shown in Fig. 2, extending across the compartment I2,surroundingthe up- 45 per portion of the evaporator I9 and secured tothe liner I5 on a leg 32. I also provide supply and discharge passages33 and 34, respectively, opening into the compartment II on oppositesides of a baille 35 extending across the compart- 50 ment andterminating short of the top thereof. Upon reference toFig. 2, it willbe apparent that when the evaporator I9 is rotated in a counterclockwisedirection, as indicated by the arrow I8a. the air will be drawndownwardly from the open- 55 ing 34 into the compartment I2 and will beforced across the compartment by the fins 25 on the evaporator I9, thepath of the air being indicated by arrows in the Fig'. 2. The air iscooled in circulating from one side of the compartment to the other overthe fins 25 and the surface of the evaporator I9 and will then flowupwardly through the opening 33 into the compartment Il, wherein it willcirculate up over the baille 35 and return downwardly on the other sideto the passage 34. Frost which may be collected on the evaporator I9 dueto the condensation and freezing of moisture thereon will be scraped offby the baille 21 and will fall to the bottom of the compartment fromwhence it may be removed.

, It is readily apparent that the formation of such frost will insure avery small clearance between the baille 21 and the fins 25 and willthereby provide an efficient circulation of air and a minimum film ofair between the baille and the evaporator. The position of the baille21` may be selected to direct the air as desired, and also to remove thefrost so that it will be collected where it may be conveniently removed.IIn the cabinet shown the compartment yI2 is provided with a door 36which may be opened to afford access thereto.

The circulation of air over the compressor casing I8 is accomplished ina manner similar to that employed for the evaporator. When the casing I8is rotated in a clockwise direction, as shown, air will be drawn throughthe louvers I1 at the right-hand side of Fig. 3, will be driven throughthe compartment I3 by operation of the fins 26, and will leave by way ofthe louvers I1 at the left-hand side of the casing so as to cool thecondenser, and also the motor 23. The path of circulation of the air isindicated by arrows.

'I'his arrangement for circulatingl air minimizes the effect due to thepresence of a stagnant insulating film of air closely adjacent thesurface Y of the evaporator and the compressor casings and, for thisreason, produces a highly efficient transfer of heat between the casingsand the air.

In Fig. 4 I have shown diagrammatically a modification of my inventionin which the evaporator is maintained stationary while the baffles orscraping blades are rotated. The refrigerating machine shown comprises acompressor 31 driven by a motor 33 through a belt 39. Gaseousrefrigerant is compressed by the compressor 31 and flows to a condenserI40 wherein it is liquefied and flows in predetermined quantities througha valve 4I to an evaporator comprising hollow plates 42 and 43 spacedapart and having smooth inner surfaces. Refrigerant vaporized within theevaporator is returned to the compressor through a suction line 44. Inorder to provide an emcient circulation of air over the surface of theevaporator, I provide a plurality of baiiies or blades 45 driven by ashaft 46 which is an extension of the shaft of the compressor 31.Theseblades are arranged to rotate closely adjacent the smooth surfaceof the evaporator plates 42 and 43, and as they rotate produce a rapidcirculation of air about the evaporators and also prevent theaccumulation of any substantial amount of frost thereon. It is evidentthat if desired other blades may be provided to rotate adjacent theouter surface'of the evaporator to further increase the circulation ofair and prevent excessive collection of frost. Theblades i5 mayobviously be driven by a separate motor should it be desired to maintainthem in opera tion continuously regardless of the operation of thecompressor.

From the foregoing it is apparent that I have provided a highlyefilcient arrangement for transferring heat between the surfaces of arigid heat exchange body and a iiuid medium surrounding that body.

Although I have shown particular embodiments of my invention as appliedto refrigerating machines, further modifications will become apparent tothose skilled in the art. I do not, therefore, desire my invention rtobe limited to the particular arrangement shown and described, and Iintend in the appended ,claims to cover all modifications within thespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A heat exchange device including a body having a fluid therein, aplurality of parallel fins on said body and arranged circumferentiallyabout the same, and means including a baille having a portion thereofarranged between said fins for producing a turbulent flow of coolingfluid about said ns, said body and said baille being relativelyrotatable.

2. A heat exchange device including a body having a fluid therein, aplurality lof parallel fins on said body yand arranged circumferentiallyabout the same, and means including a baille having portions adjacentthe sides of said fins for producing a turbulent `,flow of cooling duidabout said fins, said body and said baille being relatively rotatable.

3. A heat exchange device including a body having a fluid therein, aplurality of parallel fins on said body and arranged circumferentiallyabout the same, and means including a baiiie having portions adjacentthe sides of said fins and adjacent7 the surface of said body forproducing aturbulent ow of cooling fluid about said fins and said body,said body and said bame be- -ing fluid about said ns and for removingforeign matter Vfrom the fins and the surface of said body, said bodyand said comb-like baille being relatively rotatable.

5. An evaporator for refrigerating machines including a body havingrefrigerant therein, a plurality of parallel fins on said body andarranged circumferentially about the same, and means including a baillehaving portions arranged between said fins for producing a turbulentflow of uid about said evaporator and for removing frost or foreignmatter from the surface of said evaporator, said body and said baillebeing relatively rotatable. f

6. A heat exchange device including abody having a fluid therein, acabinet providing a compartment surrounding said body, a plurality ofparallel fins on said body and arranged circumferentially about thesame, and means including a baffle secured to the walls of saidcompartment and having portions adjacent the sides of said fins andadjacent the surface of said body for producing a turbulent flow ofcooling fluid about said fins and said body, said body and said baillebeing relatively rotatable.

7. A heat exchange device including a body having a fluid therein, acabinet providing a compartment surrounding said body, a plurality ofparallel fins on said body and arranged circumferentially about thesame, means including a baille having portions adjacent the sides ofsaid ns and adjacent the surface of said body for producing a flow ofcooling fluid about said ns and said body, said body and said baillebeing relatively rotatable, and means including an arcuate baillesecured to the walls of said compartment for directing the circulationof said cooling fluid through said compartment from one side to theother side thereof.

8. A refrigerating machine including a compressor casing and anevaporator arranged for rotation about a common axis, a plurality ofparallel ns on said compressor casing and `arranged circumferentiallyabout the same, a plu- .rality of parallel fins on said evaporatorandarranged circumferentially about the same, and means includingbailles having portions arranged between said fins for producing acirculation of air about said casing and about said evaporator.

9. A heat exchange device including a body having a vaporizablerefrigerant therein, a cabinet provided with a food storage compartment,a plurality of parallelfins on said body arranged circumferentiallyabout the same, means including a baille having portions adjacent thesides of said ns and adjacent the surface of said body for providing aturbulent ilow of air about said body, said body and said baille beingrelatively rotatable, an-d means utilizing the movement of air caused bythe relative movement of said body and said baille for directing astream of cooled air through said food storage compartment.

10. A heat exchange device including a body having a vaporizablerefrigerant therein, a cabinet provided with a food storage compartment,a baille extending vertically upward in said food storage compartment,the upper end of said baille being spaced from the top wall of said foodstorage compartment, a plurality of parallel ns on saidbody and arrangedcircumferentially about the same, means including a second baille havingportions adjacent the sides of said fins and adjacent the surface ofsaid body for providing a turbulent ilow of air about said body, saidbody and said second baille being relatively rotatable, and meansutilizing the movement of air caused by the relative movement of saidbody and said second baille for directing a stream or" cooled airthrough said food storage compartment, said lastmentioned meansincluding an air supply conduit extending from one side of said baillein said food storage compartment adjacent said body and an air dischargeconduit extending from adjacent said body to the opposite side of saidbaille in said food storage compartment.

11. A heat exchange device including an evaporator having a vaporizablerefrigerant therein, a cabinet provided with a food storage compartmentand an evaporator compartment, a plurality of parallel fins on saidevaporator and arranged circumferentially about the same, means inc1uding a baille having portions adjacent the sides of said iins andadjacent the surface of said evapo- .rator for providing a turbulentilow of air about ALEXANDER R. s'rEvENsoN,y JR.

